Actually, Bjorn Lomborg never really went away. Armed with his labyrinthine economic models, the Danish statistician is a frequent go-to commentator for media outlets seeking some “balance” in their global warming coverage. He gladly obliges them by trash-talking the Kyoto Protocol, pointing out that polar bears will be just fine when the ice caps melt, and serving up other mathematically derived opinions that cut against conventional environmental wisdom. Lomborg has written a new book, Cool It: The Skeptical Environmentalist’s Guide to Global Warming, that’s landed him choice coverage in sympathetic outlets like the Wall Street Journal and Fox News. Lest anyone else be too inclined to take him seriously, it’s worth remembering that Lomborg’s sketchy science has been pretty soundly thrashed by Scientific American, Grist, and famed biologist E.O. Wilson, who called his first book “a sordid mess.” —Keith Goetzman.